On Planet LV1201, three species vie for supremacy over an inhospitable world that contains the remains of a fourth, long-dead but advanced species. The Weyland-Yutani corporation has established a facility on LV1201, engaged in archaeological exploration of ancient technologies, and perhaps more sinister research. A group of Colonial Marines are dispatched to investigate when the facility on LV1201 ceases all communications. The xenomorphs are an alien species with a hive-like mentality that have long thrived on LV1201. The aliens will use claw, tooth and tail, even spilling the acid blood of countless drones to protect the queen and drive out the human incursion. A third species, know to the humans as "Predators" seem to live for the sport and honor of the hunt. LV1201 has been a favored hunting ground where Predators could prove their mettle against the fearsome alien hive. When the humans capture two Predators, a third emerges to hunt for his brethren and pursue the challenge of hunting humans. Three deadly species in such close quarters can only end in a high death toll, where the lucky ones escape, and the truly fortunate escape with their sanity intact.

Aliens versus Predator 2 is a first-person shooter which presents three single-player games (one for each species) and multiplayer support with a variety of individual and team match modes.

United States Army Ranger B. J. Blazkowicz has been recruited by the Office of Secret Actions (OSA). Heinrich Himmler is heading an initiative to create an unstoppable force to win the Second World War by pursuing facets of the ancient occult as well as advanced genetic and biomechanical experiments. Blazkowicz faces Nazi soldiers, SS elite guards, undead, and genetic monstrosities as he unearths Himmler's esoteric plans for world domination. By engineering super-human soldiers that combine the worst of man and machine, Himmler's scientists have created monsters to assume the role of Dark Nights – which the SS Paranormal division can use to raise prince Heinrich and his undead minions from their thousand-year slumber. Should Himmler succeed in restoring Heinrich's ancient evil to power, the human race will suffer a fate far worse than even the Nazis have plotted.

Return to Castle Wolfenstein includes a multiplayer component with objective-based team play. These games pit teams of Axis soldiers against Allied fighters, with each side composed of up to four specializations: Soldier, Medic, Engineer and Lieutenant.